Self-leveling storing and dispensing apparatus



Jul 28, 1953 .J. G. FlTZ PATRICK SELF-LEVELING STORING AND DISPENSING APPARATUS Filed MarCh 31. 1948 FIG.2

INVENTOR JAMES L6. F/TZPATR/CK BY W M whiz/z ATTORNEY Patented July 28, .1953

SELF-LEVELING STORING AND DISPENSING APPARATUS James L. G. Fitz Patrick, New York, N. Y., assignor to American Machine and Foundry Company, a corporation of New Jersey Application March 31, 1948, Serial No. 18,248

Claims. (Cl. 312-71) This invention relates to self-leveling, storing and dispensing apparatus of the general type shown in U. S. Patent 2,251,874, granted to William J. Gibbs on August 5, 1941, and more particularly to structure for quickly changing the capacity of such a self leveling apparatus for carrying material of one weight at one time and to another capacity for carrying material of another weight at another time.

Heretofore the capacity of self leveling dispensers of the type referred to has been changed by either connecting or disconnecting springs until the required number of active springs for supporting material of a certain weight was arrived at. In other words the total number of active springs was either increased or decreased to obtain the force necessary to counterbalance the weight of the material supported on the carrier.

It is the purpose of this invention to overcome the problem of having to connect or disconnect springs to arrive at the required combination of springs necessary to counterbalance material of any given weight and to provide a capacity changing device which will allow all of the springs to remain connected.

It is therefore an object of this invention to provide a simple adjusting device which when moved will gradually change the amount of tension to whatever is required for counterbalancing any given type of material being carried by the dispenser.

Another object is to provide a device which will enable the table modulus of resistance to motion to be varied while maintaining the spring modulus of resistance to distortion constant.

A further object is to interpose an adjustable lever mechanism in between a member which resists deformation at a uniform rate and a table through which the resistance of said member to deformation is transmitted to thereby change the resistance of the table to motion while the resistance of the member to deformation remains constant.

A further object is to provide a device for changing the degree of force exerted by counterbalancing springs on a table of a self leveling dispenser to correspond with the weight of the type of material being supported by the table while maintaining all of the springs the dispenser operati e. e

Another object is to employ a lever arm device v for gradually and uniformly changing the force exerted by a spring for the entire operative deformation of the spring while maintaining the linear distance traveled by the table constant.

Another object is to provide a single adjusting member for quickly changing the capacity of a self leveling dispenser.

A further object is to provide a device for increasing the amount of spring tension force exerted on the material carrying table of a self leveling dispenser to overcome friction existing between the material supported on the table and the stationary parts of the dispenser surrounding the path of travel of the table.

Other objects and features of the invention will appear as the description of the particular physical embodiment selected to illustrate the invention progresses. In the accompanying drawings, which form a part of this specification, like characters of reference have been applied to corresponding parts throughout the several views which make up the drawings.

Fig. 1 is a side view of the apparatus for changing the material handling capacity of a selfleveling dispenser from material of one weight at one time to material of another weight at another time.

Fig. 2 is a side view of a modified form of my invention showing how the elongated rack can be made flexible.

As mentioned hereinbefore this invention relates to the art of self-leveling dispensers of the general type shown in U. S. Patent 2,251,874 referred to above.

, To illustrate how my invention operates I have shown in Figure 1 a conventional table platform i0 for carrying and supporting material placed in the dispenser. Platform i0 is constructed and arranged to move up and down in an enclosure surrounded by material supporting guide walls 12. A downwardly extending flange or skirt l4 engages with the guide walls l2 to maintain the table ID in a horizontal position. When the table I0 is in its uppermost position it is co-extensive with the top 16 of the dispenser as shown in Figure 1.

If desired, reference may be made to copending application of Christopher Bockius, S. N. 736,479, filed March 22, 1947, showing an enclosure which assists in supporting material stored on a selfleveling carrier.

Up and down movement may be imparted to table Iii by means of either a pair of racks l8 mounted on opposite sides of the table Ill or a single rack mounted in the center of the table l0. While a pair of racks might in some cases add additional stability to the table Hi, my invention will also work satisfactorily with only a single rack or other suitable supporting means such as the sprocket chains shown and described in Gibbs U. S'. Patent 2,25l,874= mentioned above.

The rack or racks I8, depending on whether one or two racks are used, have teeth I9 which engage with similar teeth 2| of gear segments 29. coacting with each rack 18.

Rollers 22 mounted on a suitable stud orshaf'm 24 hold each rack IS in engagement with their respective gear segments 23. Thegear segments 20 are fixedly mounted on the -shai-t-.2{-.-wh;i ch. is rotatably mounted in supporting brackets 23. Supporting brackets 28 are attached to opposite sides of the base (not shown) of 'aself leveling dispenser similar to that disclosed in Gibbs-J3.- S.- Patent 2,251,874.

Inthe embodiment shown to illustrate my invention, I haveshown aleverage device consisting of a lever arm- .Ellfixedly mounted onthe'same shaftitas gear segments 20.

The. longitudinal axes-of lever arm 35 passes through substantially the same pointofjrotation as the gear segment 25. Arm 38 has two brackets 32 and 35 mounted across its length which rotatably support a suitable screw 3% at oppositeends.

The screw 38 isprevented from moving longitudinally by aknob 38 and a collar 40 both of which arefixedly attachedto the screw 36, on the outsideotbraclzets E2, andfifi as shown in Fig. 1, By rotating the screw 35. by means of knob 38, a sliding block 12, which is threaded on the screw 3.6, slides along the axial length of thescrew 36, in asuitable channel formed in the arnr3!) to changethe force applied {through said leverage device.

The sliding block 42has an eye bolt 54 projecting therefrom to which is connected the lower end Of one or more calibratedtension springs 43'. The upper end of the calibrated tension'springs lsiare connected to a suitable anchor bar 43which is adjustably attached at either end to suitableextensions of shell l2by adjusting screwslts. The adjusting screws as projectthrough suitableslots 51 formed in the extensions of shell IZ'and'permit the bar '53 to be moved up or down.

Figure .2 illustrating a modified form of my invention, shows how the rigid rack i tin-Fig. l-can be readily made flexible. The flexible rack consists of a' plurality of sectors 53 which are'interconnected by suitable hinges Each sector 59 is provided with a lock lug 6S and'a corresponding indentation lo which engages with thelock lug 680i? adjoining sector 5i: and provides-rigidity to the flexible rack when in vertical position. When the flexible rack is lowered, roller 54 engages with a suitable guide plate efi' andcauses the rackto move alongahorizontal-path of travel.

One or-more gear segments 2&(Fig. 2) the number depending on how man-yracks are used, are fixedly mounted on the shaft 26 in the same manner as mentioned above in connection with Fig. 1. Roller 64, loosely mounted onstud 66, holds the flexible rack 59 in engagement with the gear segment 23.

A torque is applied to theflexible rack Mat the point where gear a segment 2% intermeshes witlr the teeth of the rack. This torque is transmitted to the interlocked segments 59 and assists in maintaining the flexible rack rigid when in vertical position.

An adjustable lever arm is mounted on shaft 26 of Figure 2 to permit the amount of spring tension exerted on the flexible rack or shaft to be changed. Since this adjustable lever arm is of the same construction and arrangement as arm 30 shown in Figure l, and serves the same purpose, it has been omitted from Figure 2 for purposes of simplicity.

The operation of my invention may bebriefly described as follows:

Material to be stored in the dispenser should preferably be of uniform weight and size. It is alsopossibleto-storematerial that does not have uniform weight or thickness in a self-leveling dispenserbytheuse.oftote boxes. In this case the toteboxeswill have a thickness or height which correspondsproportionately to the weight of the material contained in the tote box.

V/hen-such-material or tote boxes are placed on top,.o.f--the table Ii], they will cause the table to descend adistance correlated with the weight of the material. By, adjusting the knob 38, the amount of spring tension'iorce exerted by the springs 46 through the. leverage, system Sll'and 20' "OI1 the rack l8 may. be changed so thatthe, amount of spring tension force needed to counterbalance'theweight supported on the table is reached;

Thereafter anydecrement or increment of material removed from or added to the material stored on top ofthe-table i6 will cause the entire stack oi rnaterial to be automatically raised or lowereda distancefcorresponding to the weight of eachdecrement" or increment. the uppermost article-onthestack'or the top of'the material'supportedon the platform It will be always maintained at a constant uniform level above the top, of the dispenser l6 due'to the automatic rise or descent'of the table just mentioned.

Bymaintainingthematerial at a uniform level above the. top of the dispenser l6, an operator or a; workercanreadily remove material from the dispenser" or add material to the dispenser withouthaving to eitherlift or lower articles substantialdistances. known, lifting or lowering' material has a tendency'to cause fatigue on the part of a worker and thus lower his efficiency. It also'has the disadvantage that mere lowering and raisingof material by hand is usually unproductivegeflort' and some cases can even cause. bodilyharm; to a worker.

As material is stacked on the table ID, it causes the racks l3 mounted on opposite sides ofthetable l0. to descend. Racks [3, whichare heldin engagement, with gear segments by the means'ofthe rollers 22 cause the gear segmentsja. to rotate shaft 26. in its supporting brackets-28. As the gear segments 2i: rotate in the-bearing brackets 28. itcauses the arm to swing. about the same pivot .point As the arm 30. swing s aboutthesame pivot, point it the spring 46,, orsprings if several are used, to be stretched. The. amount of, force exertedby the springs 48 on the rack $8 or vice versa will depend upon the position of the block 42 along the length of the screw 35.

Iftheblock 42. is closely adjacent to the, knob 38,the;sp,ring.46 will exert a greater leverage on the rack. I8 through the gearsegment 20 than it would; exert if. theblock 42-. were positioned on .the screw closely adjacent to the collar 4 0.

As a consequence, when the position of the block 42 on the screw 36 is changed by rotating the knob 38, the amount of force exerted on the racks I8 will also be proportionately changed.

The force exerted on the rack or racks l8 will at all times be proportionate to the weight of the material supported on the table l0. Therefore when the block 46 is set by means of knob 38, at a point along screw 36 which counterbalances the material, the top of the material or stack will always seek the same level regardless of whether material is added or removed from the stack.

If the top of the stacked material tends to go above or below the predetermined level when the dispenser is loaded or unloaded, knob 38 may be turned to apply more or less tension to the table II] to correct this error and bring the spring tension and material being handled into balance.

In the event bulk material is stored in the dispenser, friction between the material and the shell I 2 may cause the dispenser in some cases to go out of balance especially when material is being removed from the dispenser. In this case by merely turning the knob 38 to apply additional tension to the carrier table ID, the increased friction will be overcome so that the dispenser will operate normally.

The operation which has just been described in connection with Figure 1 is also applicable to the structure shown in Figure 2. The only difference between Figures 1 and 2 is the fact that the table supporting rack 50 has been made flexible in Figure 2 so that as it descends the roller 54 engages with the guide or cam track 56. This causes the rack made up of segments 50 to bend, causing each segment 50 to pivot on its hinges 52 and to assume a horizontal path of travel.

When the rack, made up of segments 50 and hinges 52, is held in raised position, a torque is effected which assists the interlocking lugs 68 and corresponding indentations iii of each se ment 50 maintain the rack rigid to support the table.

The mechanism described above for employing an intermediate lever mechanism interposed between calibrated springs and the material supporting table has the advantage that the capacity of the self leveling dispenser may be easily changed by varying the operative length of the lever arms. As a result the usefulness of such storing and dispensing apparatus has been greatly increased.

The invention above described may be varied in construction within the scope of the claims, for the particular device selected to illustrate the invention is but one of many possible embodiments of the same. The invention, therefore, is not to be restricted to the precise details of the structure shown and described.

What is claimed is:

1. A self leveling material storing and dispensing apparatus comprising, a housing, a table reciprocable vertically between the top and bottom of said housing for supporting material so that the top of the material is maintained at all times at a predetermined level above the top of said housing, a flexible member for supporting said table, a rotatable member coacting with said flexible member to raise and lower said table a distance correlated with the Weight of each decrement and increment removed from and added to the material on said table, a lever arm interconnected with said rotary member for rotation therewith, a calibrated spring connected at one end to said housing and at the other end to a movable connection mounted on said lever arm, and mechanism for changing the position of said movable connection along the length of said lever arm to change the amount of force exerted by said rotary member on said flexible member tothereby change the material carrying capacity of the dispenser.

2. Apparatus of the self leveling type for storing and dispensing material comprising, a housing, a platform for supporting material in said housing wherein said material has unrestricted upward movement, elongated flexible members coming up from beneath said table for lowering and raising said platform between predetermined limits, said members being constructed to be maintained rigid when arranged in a substantially straight line and when force is applied axially thereto, a calibrated spring device for exerting a proportionally increasing degree of resistance corresponding with the amount of deflection of the spring, mechanism interconnecting said spring device with said elongated flexible members for counterbalancing the material supported on said platform by means of said spring device, and means for proportionately changing the amount of force exerted by said spring device on said elongated members to correspond with the weight of material being supported on said platform to thereby maintain the top of material of one weight at a constant predetermined level at one time and the top of material of a different weight at the same level at a difierent time regardless of whether material is added to or removed from the material supported on the platform.

3. A self-leveling dispensing apparatus for storing and dispensing material having unrestricted upward movement in said apparatus, a material supporting platform constructed and arranged to move up and down in said dispensing apparatus, springs having a uniform resistance to distortion mounted in said apparatus, a lever interconnecting said springs with said platform to counterbalance material supported on said platform with the resistance of said springs to distortion to thereby always maintain the top of the material stored on said platform at a constant predetermined level, and mechanism for changing the effective length of said lever to thereby change the effective force of the springs to support material of different weight at different times.

4. Apparatus of the self-leveling type for automatically raising and lowering material placed on a platform a distance corresponding to each increment or decrement added to and removed from the material on said platform to maintain the top of the material at a constant predetermined level, comprising a frame, a platform movable between the top and bottom of said frame, springs having a uniform rate of resistance to distortion mounted within said frame, a lever for transmitting the resistance to distortion of said springs to said platform, and mechanism for changing the effective length of said lever to change the force exerted on said platform by said lever to thereby change the distance said platform is moved by materials of different weight.

5. Apparatus of the self-leveling type comprising, a frame, a platform movable up and down within said frame, a flexible rack having a plurality of segments for raising and lowering said platform, hinges interconnecting said seg- 75 ments;0n= one; sidehteethformed-on" the; opposite for, the same, distance tmwaled by.. said. gear side ofyeach ofsaid segments' gear; teeth coa ctteeth; ingwithteethofsaidseg-mentstoraise and low- I JAMES L, G. FITZ PA I RICK,

erzseid-fiexiblerack and toapply a torque thereon at the: pointof engagement with said teeth to 5 References eiin the. file of this p fimassist: immaintaining said rackrigid-when sup- UNITED STATES PATENTS parting said-platform and a spring having a uni- Number Name Date form rate of resistance to dlstol tlon enacting with v saidggear teeth to exert a degree of force therem -1 1932 onproportionalto thedistance traveled by said 10 0 nney May 1941 teeth, and-means for changing the amount of Gibbs 53 1941 force; exerted bysaid spring on said gear teeth 

